[Remote suggestions] Report time distribution of triggers

components/ntp_snippets/remote/remote_suggestions_scheduler_impl.h

Index: components/ntp_snippets/remote/remote_suggestions_scheduler_impl.h
diff --git a/components/ntp_snippets/remote/remote_suggestions_scheduler_impl.h b/components/ntp_snippets/remote/remote_suggestions_scheduler_impl.h
index 7fe94d6e86c8ca04d273fa5c78caee9d5ea3773b..9921f51489adfa7813a603af9077d42b1c2a4b24 100644
--- a/components/ntp_snippets/remote/remote_suggestions_scheduler_impl.h
+++ b/components/ntp_snippets/remote/remote_suggestions_scheduler_impl.h
@@ -93,7 +93,7 @@ class RemoteSuggestionsSchedulerImpl : public RemoteSuggestionsScheduler {
 
   // Checks whether it is time to perform a soft background fetch, according to
   // |schedule|.
-  bool ShouldRefetchInTheBackgroundNow();
+  bool ShouldRefetchInTheBackgroundNow(base::Time last_fetch_attempt_time);
 
   // Returns whether background fetching (for the given |trigger|) is disabled.
   bool BackgroundFetchesDisabled(TriggerType trigger) const;
@@ -144,6 +144,9 @@ class RemoteSuggestionsSchedulerImpl : public RemoteSuggestionsScheduler {
   RequestThrottler request_throttler_active_ntp_user_;
   RequestThrottler request_throttler_active_suggestions_consumer_;
 
+  // To make sure we only report the first trigger to UMA.
+  bool time_until_first_trigger_reported_;
+
   // We should not fetch in background before EULA gets accepted.
   std::unique_ptr<EulaState> eula_state_;